Need advice on helping/dealing with my uncle

So I’d say there’s a combination of a few things going on here. I’ll lay them out and you can parse for yourself how relevant each one may be OP.

1) There’s definitely something to people going travelling and not expecting things to change, it’s a process everyone I know who’s moved has had to adjust to. The reality is that while you may leave for a better life, you also leave behind those at home and they all had to adjust. They won’t all just sit around missing you and your elderly uncle couldn’t be left alone to care for himself, I’m sure part of you is happy if he’s getting care that he needs now without you even if it has put a small strain on your own relationship. And that’s a sacrifice you chose to make, whether you realised it or not, with both him and other family and friends. You shouldn’t feel guilty for that, and families can adjust, but you have to accept that and allow it to happen if the move was right for you. You’ll only end upset if you expect everyone to sit around with a you-shaped hole in their lives, it’s not how it happens and that’s actually a good thing for all involved on balance even if it causes some mild upset during the transition.

2) Your family were probably happy to let you care for him, but their own lack of effort when you lived here probably wasn’t because they just didn’t give a ****. Being the primary carer for an elderly relative is a huge commitment. I wouldn’t let any of my aunts and uncles rot by themselves, but I also wouldn’t go rushing to be their primary carer if someone else could handle it because I’d like the benefit of getting to live my own life where possible. That’s probably what happened with you, you took the responsibility on, even though again you may not have realised that. Then when you were gone, someone else needed to step up so they did. Again, that’s ultimately a good thing. If you were next of kin, you wouldn’t have been able to have given him the care he needed from another country. And isn’t that more important than him paying tribute to you but not having access to the care he needs?

3) Lastly, when we’re in a family and love our relatives, we’re sometimes clouded to how they may truly be seen by the rest of the world. For example no family considers themselves the village oddballs, but there definitely are village oddball families we’ve all met, it’s just their life is normal to them because it’s all they know. Why I’m saying this is that there may have been a reason you hadn’t been privy to why your family kept/keeps their distance from your uncle. I don’t mean that in terms of any big dramatic family secrets, he could just be known for being rude and unpleasant as he was to you. But when you were/are the only source of his social interaction, maybe he values that so is on his best behaviour. And when you weren’t, maybe you got a taste of why the rest keep their distance where possible. There’s always two sides to every story after all, but while you and him had a positive relationship you had no reason to question his side and assumed the worst of your family. But I did raise an eyebrow when you put their motives for ignoring him down to basically being snobby, when you also describe them as pretty sound in a later sentence.

What to do from here? That’s up to yourself, there’s no definitive answer. Are you obliged to still call and help him where possible? No, not at all. If you’re that upset about how he spoke to you, you don’t owe him anything, and if he doesn’t appreciate what you have done to take responsibility then that’s on him. But he’s also elderly and probably set in his ways, so be advised he probably won’t take responsibility and you may be left waiting forever for an apology that won’t come. So if you want him in your life, if you think you’d regret ignoring him when he’s gone one day, then your best course of action is just letting it go and accepting him for who he is.